The Dallas daily herald. [volume] (Dallas, Tex.) 1873-1887, 1887-05-05
NEW AND OLD BRIDGES.
VARIOUS STRUCTURES ACROSS BIG
STREAMS OF WATER.

The Now Harlem Bridge and How They
arc Building 1.-THE New Bridge Across
East Rlvcr-Some Famous Bridges, An
cient and Modern.
New Yorl, city is likely to be eventually
the most famous in the world on account OF
its bridges Tho one building over the Har-
lem rivor at One Hundred and Eighty-first
street will add to its Importance as city of
bridges, and another is contemplated across
East river above the Brooklyn bridge.
The foundation for the center pier OF the
bridge over the Harlem is approaching COM
pletion. When finished the bridge will be an
achievement worthy of the genius and time
expended upon it, IL will consist OF two
metallic arches, each $40 feet clear, one
of which spans the entire width Of tho river
and the other the whole distance from the
easterly bank OF the river to Sedgwick ave-
nue.. Each span consists Of six separate steel
plate arches, spaced IA feet between centers
and connected by bracing. The floor sys-
tenn is carried ON vertical columns supported
by the arches The floor is SO feet wide,
and consists of q roadway Of 80 feet and
two footwalks of Is feet each. The grade OF
the roadway is $50 feet above mean high tide.
The arched masonry approaches are as nearly
symmetrical at both ends as practicable.
In sinking the foundation for the center
pier it was discovered that fifteen feet from
the surface of tho water rock sloping down.
ward at n sharp anglo toward the center OF
the river would be encountered, and Oh this
rock rest the soft mud and sand of the river
bed. This necessita,ed the extensive use OF ex-
plosiyes. Indeed, 4; Is believed that in this
instance more rock was removed by blasting
than in any other similar work ever under
taken. AT first they used dynamite exclil-
sively; but the gases it generated caused the
men to complain Of severe headaches after
each firing. That and tho peril of handling
IL werc against it. Rackarock was then tried
with pleasanter results. Rackarock consists
of two ingredients, a fluid and solid, shipped
in separate packages, each Of which is abso-
lutely non explosive. When needed, the two
ingredients are combined by pouring GER
tain proportion of the fluid over the solid,
which is contained in bag Of the usual
cartridge form II takes but few seconds
for the oil to thoroughly saturate the cart
ridge. one of the tied ends Of which is then
cut. tho cloth case opened and the fuse in
serted. The end Is then reticd, and the cart
The bill authorizing the construction Of tho
new East river bridge passed congress in
March. The structure will so from New
York city to Long Island by way OF Black
wells Island. It is to DO $50 feet high, SPAN
ming either channel, will accommodate pas
senger and freight cars and will also have
footway. Sufficient capital is promised in
Europe to build it from the foundations OF
the piers to the last coating OF paint. It's
starting place in Now York is near the Grand
Central depot; it will be cantilever, like that
mt Niagara, and will DO three and half
miles long.
II is designed for rapid transit in tho true
sense of the term. Trains will be run at
thirty miles an hour. All vehicles will be
run over on platform cars designed for this
purpose. That it will develop and populate
Queens county and hong Island generally 10
n certainty. Cantilever means lever or sup
mort for something at a cant or angle from
wall beyond which it projects In plain
words. il is like q bracket secured to the wall
from which it runs out for tho purpose OF
bearing up a cornice or other material.
Niagara Ind the first notable cantilever
bridge, 1t has been complete and carrying
trims at speed for over two years. The road
way of this bridge runs over tho tops OF tho
towers Since it has been completed another
similar to it has been built over the river at
st. John, N. d.
Tho greatest cantilever bridge, however, is
the ono now building over the Firth OF Forth,
Scotland. Tho Firth is an arm of the sea
frequented by Great Britains largest iron
ciads, and requires bridge considerably
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